Electric switch



(No Model.) I

J. F. MGLAUG'HLIN.

ELECTRIC SWITCH.

No. 428,935. Patented May 27, 1890.

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WITNESSES:

'UNITED' STATES PATENT OFFICE.

JAMES F. MOLAUGI-ILIN, OF PHILADELPHIA, PENNSYLVANIA.

ELECTRIC SWITCH.

SPECIFICATION forming part of Letters Patent No. 428,935, dated May 27,18 90.

Application filed November 27, 1889. Serial No.33l,'774. (No model.)

To (0% whom it may concern:

Be it known that I, JAMES F. MCLAUGHLIN, a citizen of the United States,and a resident of Philadelphia, in the county of Philadelphia and Stateof Pennsylvania, .have invented certain new and useful Improvements inCombined Electric Switches and Out-Outs, of which the following is aspecification.

My invention has reference to improvements in switches for electriccircuits carryin g currents of large volu mesuch as electriclightingcircuits or electric circuits used for the transmission of power'and thesame is an improvement upon the electric switch shown and described byme in my application, Serial No. 330,154, filed November 13, 1889; andthe obj eet of my present invention is to provide locking mechanismwhereby the switch when closed will be safely locked against accidentaldisplacement, but may be opened instantaneously by a very slightmovement of a trigger provided for this purpose, and this movement ofthe trigger may be caused either arbitrarily by the hand of an operatoror by an electro-magnet energized sufliciently by the current controlledby the circuit in which the switch is employed when said currentincreases above its normal or desired strength. I have also madeprovision, in addition to this electro-magnetic cut-out, for an ordinarycut-out, such as is used in other switches or in any place in thecircuit independently of the switches. All this will more fully appearfrom the following detailed description, in which reference is made tothe accompanying drawings, which form a part of this specification, andin which I have shown, in-

Figure 1, a plan view of my improved switch with the operating-handleremoved and the switch open. Fig. 2 represents a similar view showingthe switch closed. Fig. 3 is a vertical sectional view 011 the line 00a: of Fig. 1. Fig. i is an inverted plan view showinga safety-plug orcut-out applied to the base of the switch, and Fig. 5 is a sideelevation of one of the contact levers or brushes pivoted in positionupon its supporting-bracket.

The operative parts of my switch are mounted upon a base 1 of insulatingmaterial, which may be of hard rubber, wood, and the like, but which bypreference is made of some refractory material, such as stone, slate,glass, porcelain, or asbestus. In the drawin gs this base-plate is showncircular in form; but it may be differently shaped, as will be readilyunderstood. Suitably secured upon the base-plate by screws 2 2 is acasting 3,be* ing, in fact, a sectoral plate, as shown in Figs. 1 and 2,with a cylindrical post at rising from the center of the sector, andwhich in the drawings is shown as in one piece with the sectoral plate,but which may be separately made and secured to the center of thesector. On diametrically-opposite sides of the post 4 are mountedbrackets 5 5, rising from metal plates (3, and to each of these metalplates is also secured a binding-post 7, into which the conductors S 8are clamped. One of these brackets-namely, the bracket 5-is mounted uponthe sectoral plate of the casting 3, and, if so desired,it may be castin one piece with the same.

The bracket 5 is mounted upon the insulating base-plate 1, and to eachbracket is hinged a curved contact lever or .brush 9 by a pintle 10,passing through the upper arm of the bracket, and through lugs 11 11,extending from the contact levers or brushes 9 and into the metal base 6of each bracket.

Upon the pintle 10 is placed a strong helical spring 12. One free end 13of the spring 12 bears upon the bracket 5 or 5 and the other end 14against the shoulder 15 formed on the curved lever between the lugs 1111. The tendency of the springs 12 is to throw each contact lever orbrush with its long arm toward the center of the sectoral plate 3; butthis forward movement is limited by a tooth 16, projecting from one ofthe lugs 11, coming into contact with a stop-pin 17, rising from themetal base 6 of each bracket. will be seen that if each contact lever orbrush 9 is free to follow the action of its impelling-spring 12 it willbe thrown with its long Thus it" arm toward the center of the sectoralplate 3 and will be arrested in the position shown in Fig. 1, where eachtooth 16 is represented as in contact with its stop-pin 17. In thiscondition of the device the spring 12 is under considerable strain, andif in the manner hereinafter described the long arms of the levers 9 areforced back from the center of the sectoral IOC plate the strain of eachspring 12 is considerably increased.

The pintles l0 and the springs 12 can be made as heavy as desired, andfor the purposes of my invention they should be made as heavy aspossible, for the current controlled by the switch will in part passfrom the bracket 5 into the switch-lever f) by way of the pintle 10 andthe spring 12, and in order to prevent the heating of these parts theirconductivity must be made as great as practieable.

Upon the cylindrical post i is journaled a switch-block 18, the samebeing a heavy easting formed with two wings 10 19, as clearly shown inFigs. 1 and 2. Each wing 19 is formed with acam-surface 20, which iseccentric to the cylindrical post at and with a contact-surface 21,which is in effect a segmentof a cylinder-surface concentric with thecylindrical post 4. The cam and contact surfaces meet at an obtuseangle, as is clearly shown in Figs. 1 and 2. The switch-block has acylindrical portion 22 extending above the winged portion of the same,and a handle 23,0f insulating material, is screwed onto the upper end ofthe cylindrical extension, as shown in Fig. b.

As a protection against dust and dampness a casing 21, having a centralopening to allow the cylindrical extension 92 to pass through, is used,and it will now be seen that by turning said handle in the directionindicated by the arrows in Figs. 1 and 2 the switch-block will be movedfrom the position shown in Fig. 1 into the position shown in Fig. 2. Bythis movement, comprising only a quarter-revolution, the cam-surfaces 20will first be brought into contact with the inner curved surfaces 9 ofthe contact-levers f), and will force said levers outwardly against theincreasing tension of the springs 12 until, finally, theconvexcylindrical contact-surfaces 21 bear upon the concave cylindricalcontactsurfaces of the levers orbrushes O. This last position of theswitch-block is shown in Fig. 2, and it will be seen that it securesforcible contact between extended contact-surfaces, and that thiscontact is established by a quarter of a rotation of the switch-handle.

In order to prevent the switch-block 18 from being raised from itsbearing by the manipulation of the handle, or from moving away from itsbearing by the action of gravity when the switch is fixed with itsbase-plate against a wall or a ceiling, a neck 1 is formed on the posti, and a screw-pin 25, screwed into the switch-block, engages with itspoint the said neck.

From one of the wings of the switch-block projects downwardly alocking-pin 26, which is preferably made square. This square pin extendsto within a short distance from the upper face of the sectoral plate, asshown in Fig. 3, and rising from said sectoral plate in the path of thesquare pin 20 are two stop-pins 2" 27, which are spaced a little morethan ninety degrees (90) apart, and are so located that when theswitch-block is in the position shown in Fig. 1 the locking-pin 26 willbear with one side against one of these stop-pins, and when theswitch-block is in the position shown in Fig. 2 the opposite side of thelocking-pin will be within a very short distance from the otherstop-pin, so that it will be seen the switch-block can be moved ineither direction throughout one quadrant.

Underneath one of the contact levers or brushes 9 is pivoted upon thesectoral plate 3 a lever 28, extending with one end through a slot inthe casing 21, and is there provided with a handle 29. The other orinner end of the lever 28 is formed into a tooth or dog, as shown,having a fiat face 30. As will presently be seen, this lever 28 has thefunction of a trigger, and it will hereinafter-be referred to as such.The inner end of this trigger-lever is thrown inwardly by the action ofthe trigger-spring 31., but is limited in its inward movement by the pin32, with which the long arm of the lever comes into contact.

The arrangement of the parts is such that when the switch-block isturned from the position shown in Fig. 1 into the position shown in Fig.2 in the direction of. the arrows the locking-pin 26 will in the courseof its movement bear upon the short arm of the triggerlever and forcethat arm backward against the action of spring 31 until it has clearedthat arm, when the dog end of the latter will again be forced inwardly,as shown in Fig. 2, whereby the switch-block becomes locked in position,so that it can be moved in neither direction by the handle 23.

For opening the switch it is necessary to move the trigger out of thepath of the locking-pin 26, and this can be done by turning the outerend of the triggcr-leveravery short distance, as indicated by dottedlines in Fig. 2. After this has been done the switch-block is unlocked,and may now be moved back to the position shown in Fig. 1; and I haveprovided means for effecting this movement automatically and with greatrapidity. For this purpose there is formed on the under side of theswitch-block an annular recess 33, in which is located a helical spring3-1, one end of which is secured to the switch-block and the other endto the segmental plate, as is clearly shown in Fig. 3. The tendency ofthis spring is to turn the switch-block in a direction opposed to thatindicated by the arrows, so that when the switch-block is turned fromopen to closed the spring S-t is put under tension,and when by pullingthe trigger, as hereinbefore described, the switch-block is released itis rotated with great rapidity from closed to open. Instead of pullingthe trigger by hand, it may be pulled by the force of an electro-magnet35, which electro-magnet may be, and preferably is, included in thecircuit controlled by the switch, and the core and coils of which are soproportioned that it will be sufficiently energized to pull the triggeronly when the current attains greater strength than is intended to becarried by the circuit. For this purpose it will be understood that thetriggerlever, or at least the outer end of the same, must be made ofiron.

One end of the magnet-coil is connected with the binding-post 7,connected with bracket 5, and the other end of the magnetcoil isconnected with the line. Thus by the use of the trigger-lever forlocking and releasing the switch-block, which trigger-lever has only asmall movement, and which may be effected by a slight force, I amenabled to utilize an electro-magnet operating in conjunction with it asan automatic electro-magnetic cut-out. I am, however, not deterred bythis from using also an ordinary safety plug or cut-out, and I haveshown such device connected with my switch.

The insulating-base 1 has formed on its under side a recess 36, in whichis placed a band 87 of easily-fusible metal, one end of which isconnected with a binding-post 38, mounted upon the top of theinsulating-base, and the other end is connected with the binding-post 7of the bracket 5'. If this safety plug is used as an auxiliary to theelectromagnetic cut-out, the binding-post 38 forms one terminal of thecircuit and the free end of the coil of the electro-magnet forms theother end of the circuit. If the safety-plug is not used, one terminalof the circuit is still formed by the free end of the coil of theelectro-magnet and the other terminal by the binding-post 7 of thebracket 5.

If the safety plug alone is used without the electro-magnetic cut-out,the terminals of the circuit are formed by the binding-post 38 and bythe binding-post 7 of the bracket 5, while if neither the safety-plugnor the electromagnetic cut-out is used the terminals of the circuit areformed by the two binding posts 7.

Having now fully described my invention, I claim and desire to secure byLetters Pat ent- 1. In an electric switch, the combination, with arotary switch-block operating in conjunction with suitablecontact-brushes, of a trigger for locking the block in its closedposition, an electro-magnet for moving the trigger to unlock theswitch-block, and a spring for automatically opening the switch when theblock is unlocked, substantially as described.

2. In an electric switch, the combination, with a rotary switch-blockoperating in conjunction with suitable contact-brushes, of a trigger forlocking the block in its closed position, an electro-1nagnet energizedby the current controlled by the switch for moving the triggerto unlockthe switch-block, and a spring .for automatically opening the switchwhen the block is unlocked, whereby the circuit is broken when thecurrent exceeds a predetermined strength, substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

JAMES F. llilOLAUGHLIN.

lVitnesses:

EDWIN F. GLENN, HERBERT P. KER.

